Coated object and process of making the same



Dec. 29,` 1936.

E. H. TRUSSELI..Y 2,965,769

COATED OBJECT AND PROCESS OF MAKING THE SAME Filed March 6, 1934Patented Bec. 29, 1936 ATE UNITED s PATENT criss COATED OBJECT ANDPROCESS 0F MAKING THE SAME `Emory H. Trussell, Newark, N. J., assignorto lBeckwith-Chandler Company, Newark, N. J., a corporation of NewJersey This invention relates to coated objects and to the method ofproviding surfaces with an improved nish for decorative or protectivepurposes. The improvement pertains generally to the surfacecharacteristics of lacquer coatings.

Heretofore in the production of a smooth iinish on rough surfaces, suchas Wood or metal with file marks, pit holesY etc., with cellulose esterlacquers and particularly cellulose nitrate lacquers seriousdifficulties arose from the use of the strong solvents of the nitratelacquer in that they dissolve the undercoaits which were used to buildup the `priming and filling coats for the rough object. The undercoatsbecome swelled and more or less raised out of the imperfections in thesurface and -onA the Aevaporation of the solvent draw back down to anirregular film showing indentations for each of the rough spots in thesurface of the object coated. Furthermore in the building of a| quickair drying finish on rough objects of this nature it is very desirableto use undercoats which not only stick to the surface ofthe object andiill the imperfections in the surface, but also dry hard quicklyprincipally by the evaporation of solvents. For this purpose primers andsurfacersbuilt around a cellulose ester base, and particularlynitro-cellulose base, have been and are used very extensively. Now whenthis type of undercoat is used and the finish or color coat of celluloseester lacquer are thereafter applied, not only is there a dissolving ofthe undercoat which results in the swelling and pulling out of theimperfections in the surface of the, object coated but also when thesolvents evaporate the entire surface takes on a soaked in Iormicroscopic pitted appearance due probably to a complete amalgamation ofthe two films. lIn order to overcome this appearance, it is necessary torub andpolish the surface, when it has thoroughly dried, with anabrasive and polishing material.

The aforementioned diiiiculties are somewhat overcome in the productionof cellulose ester -finishes at present, by the use of undercoatsv nessundesirable for a good decorative finish.'

This unevenness can be and is removed by the rubbing and polishingoperation after the lacquer has dried thoroughly.

In the present invention the above mentioned. difliculties due to thedissolving of one coat by the application of succeeding coats areovercome by using as a finishing coat of lacquer 'over a cellulose esterlacquer, a composition containing as its base cellulose ethers suchl asbenzyl and ethyl cellulose which are soluble in coal tar hydrocarbonssuch as benzene, toluene, xylene and high flash solvent naphtha ormixtures of these hydrocarbons with relatively small proportions ofcellosolve (generally known to be mono-ethyl ether of ethylene glycol)or one or more alcohols such as butanol, the amyl alcohols, etc. Thesehydrocarbon materials or the aforesaid mixtures are not solvents for thecellulose ester iilms and by taking advantage of this fact the celluloseether coatings may be applied over a base of nitrocellulose or celluloseester undercoat Without soaking in or softening to the pointy that thebase coat is drawn from imperfections in the surface to be coated.

To more specifically explain the present invention, the surface of theobject to be coated may be coated with primer and iiller ofnitrocellulose base, and sanded smoothly when dried to get a perfectlylevel or smooth surface. Then a finished decorative coat or coats ofbenzyl cellulose base lacquer are applied. The resulting finish whenproperly formulated for the method of application will dry to a smootheven surfaceV not showing any of the imperfections in the surface coatedand not having the soaked in or micro pitted appearance. If, however,the same nitrocellulose base had been used in the nished coat oflacquer, the solvents would have dissolved the nitrocellulose undercoat`and the resulting dried lm would have been rough and uneven with asoaked in or micro pitted appearance.

In certain instances, the surface of the object to be coated may firstbe primed with other types of material such as drying oil base orsynthetic resin base material. Then after they are sufiiciently dried anintermediate coating or filling coalt of cellulose ester suchas'cellulose nitrate is applied, thoroughly dried, sanded and a topcoating of the cellulose ether lacquer vapplied as a nish coat. By thismethod the same objects of the invention are accomplished.

An object of the' present invention is to provide a processby whichsolid objects are produced having smooth or glossy finishes by the useof lacquer materials.

A further object is to provide coated articles,

l the surfaces o'f which have a finish that is practically free fromimperfections that are ordinarily encountered in lacquer coatings v-thathave not received a rubbing or polishing treatment.

From the aforementioned facts, it can be seen that a still furtherobject of my invention is to produce a quick drying finishfor wood,metal, and like objects, as well as fibrous sheets. For the purposes ofthe present invention, cloth or felt or other sheet materials may beconsidered solid objects. The finish is smooth or glossy as may Ledesired without the laborious task of rubbing' and polishing` the nalcoat. The success of my invention lies in the fact that a celluloseether coating, and more specifically a benzyl or ethyl cellulosecoating, containing a solvent mixture that does not dissolve thepreceding'coat which is of a cellulose ester base, more specificallycellulose nitrate or acetate, when the finishing coat is superimposed onthe cellulose ester coating.

'Ihe present invention is illustrated in the accompanying drawing, inwhich:

Fig. 1 is a sectional view showing a supporting element with a surfacehaving an inner' coating of nitrocellulose or cellulose ester basematerial and an outer coating of cellulose ether base material; and

Fig. 2 is a sectional view showing a supporting element with asurfacehaving a primer coat of oil base or oil and resin base material,an

intermediate coat of nitrocellulose or cellulose ester base material andan outer coat of cellulose l ,from pigmented .or from clear liquidcompositions. The rate of evaporation of the solvents used can beregulated, in the well known manner, from a very rapid rate, like thefastest drying lacquers, to a medium speed comparable to that of themore rapidly drying enamels.

'Ihe various ingredients employed in the lacquers are selected toprovide compatible mixtures as is understood in the art. For instance,ethyl cellulose is considered compatible with natural resins such asdamar as well as both the phenol aldehyde and the resins of the alkydtype including for instance glycerol phthalate synthetic types, bothpure and modied. On the other hand, the benzyl cellulose is notconsidered compatible with the majority of the natural resins such asdamar, but it considered compatible with those of the synthetic typesmentioned above. Rapid developments have been and are being made in thefield of synthetic resins. Exiellent results have been obtained withlacquers containing combinations of benzyl cellulose and glycerolphthalate synthetic resins. I have prepared filmsl that are dry andclear and with very bright glossy surfaces, from combinations in whichthe proportions of cellulose ether to glycerol phthalate resins .variedfrom equal parts of cellulose ether and` resin to cases where four or veparts' of the resin to l Parts Tale 150 Zinc nxidn 150 Drynitrocellulose I 100 Tricresylphosphate 35 Blown castor oil 40 Solventmixture composed of proper balance of ester solvents (such as ethyl,butyl, or amyl acetates) alcohols (such as butonal, ethanol, etc.) andhydrocarbons (such as toluene, xylene, or even portions of fastevaporating petroleum naphthas) It is understood that the hydrocarbonsin the above formula are included merely as diluents in the well knownmanner and proportions. The proportions are limited only to such anextent as will cause no precipitation of the nitrooel` lulose material.

The. composition'of this undercoat may be varied widely as long as itadheres to the metal surface, fills the imperfections and is built on anitrocellulose, or cellulose ester base insoluble in toluene, xylene,etc.,. or mixtures of these hydrocarbons and alcohols containing a majorportion of hydrocarbon. After this undercoat is dried, it is rubbed, bywhich is meant sanded smooth with fine abrasives. Then a finish coat ofthe following composition may be applied:

- Parts Antimony oxide 230 Plastic alkyd resin 230 Benzyl cellulose lowviscosity -50 Xylenn v 540 Butanol 85 The composition of this finishedcoat may be varied between wide limits as long as it is built around acellulose ether base and is composed of ingredients that are compatibleand soluble in the solvent mixture used. This finish may be made invarious colors or clear.

Ezample'2.-As another example of my invention, I mayuse as a primingcoat for a metal surface a lcomposition of a drying oil type oroxidizing synthetic resin type as follows:

Drying oil type of undercoat:

l Parts* Pigment-mixture of iron oxide and inerts or any suitablemixture known to one familiar with the art -e 100. Fixedvehicle-composed of mixture of 'drying oils such as linseed andChinawood oils with resins s uch as East India resin,fester gum. etc.properly blended and heat treated to sive desired drying time familiarto one in the art 50' Timmer-usually petroleum distillate or mixturethereof with turpentine 50-60 oxidizing synthetic Vresin types ofundercoat:

Pigment of suitable mixture. 100 Resin such as of the alkyd type 40.

Solvent vauch as xylenel or mixed solvent suitable for purpose l00 2.A'process of manufacturing a coated metal object, whichvprocesscomprises applying a cellulose ester lacquer to a surface of saidobject,

drying and rubbing the coating formed on said,

mitting the cellulose ether lacquer coating to dry to thereby form asmooth, finished surface.

3. A process of manufacturing a coated metal object, which processcomprises applying to a surface of said object a priming coat, thenapplying a cellulose ester lacquer coating and finally a cellulose etherlacquer coating, thesaid cellulose ether lacquer applied to saidcellulose ester lacquer coating containing hydrocarbon solvent materialthat is not a solvent for the cellulose ester, thereby forming a smooth,finished surface.

4. A process of manufacturing a coated metal object, which processcomprises applying to a 'surface of saidobject a coating containing acellulose plastic that is not dissolved by low boiling hydrocarbonsalone, applying directly to the surface of said coating a solution ofcellulose v' ether in a solvent containing low boiling hydrocarbonliquid in such proportion that the solvent c doesI not soften the saidcellulose plastic coating, and permitting the said solution to dry onthe said rst coating to thereby form a smooth, finished surface.

5. A process of manufacturing a coated metal object, which processcomprises applying the following composition to a surface of the saidobject to form a coating:

Talc 150 Zinc oxide 150 Nitrocellulose 100 Tricresyl phosphate Blowncastor oil Solvent 1100 applying to the coating resulting from the aboveapplication the following composition:

Parts by weight Antimony oxide 230 Plastic alkyd resin 230 Benzylcellulose of low viscosity 50 Xylene 540 Butanol 85 and permittingdrying of the resulting object to form a smooth, finished surface.

6. A process of manufacturing a coated metal object, which processcomprises applying to a surface of the said object a priming coatcontaining 100 parts by weight of pigment and 100 to 140 parts by weightof a mixture of binder material and solvent, applying to the primingcoat resulting from the above application the following composition:

applying'to the .surface of the coating resulting from the applicationofthe last-named composition the following composition:

Parts by weight Parts by weight Antimony oxide 2 30 Plastic alkyd resin230 Benzyl cellulose of low viscosity 50 Xylene f 54;()` Butanol -85 andpermitting drying of the resulting object'to form a smooth, finishedsurface.

7. A process of manufacturing a coated'lnetal object, which processcomprises applying toa surface of the said object a coating containingcellulose plastic that is not dissolved by lowboiling hydrocarbonsalone, applying directly vto the said coating -a cellulose etherlacquer, the solvent in which contains low-boiling coal tar hydrocarbonliquid material in predominating proportions as compared with otherconstituents of the said solvent, thereby'inhibiting softening'uniformly smooth'surface characterized by, being free from that pittedappearance resulting from the application of cellulose ester coatingcompositions to inner coatings of cellulose ester.

9. An article of manufacture produced by the metal supporting elementhaving a plurality of coatings thereon including a priming coat, anintermediate coating of cellulose ester-containing material and asuperposed outsidev coating of cellulose ether-containing material,ltheV latter coating having a uniformly smooth surface characterized bybeing free from that pitted appearance resulting from the application ofcoatings prcess of -claim 3, the said article comprising a 35 ofcellulose ester4 to inner coatings of cellulose ester.

10..An article of. manufacture produced by the process of claim 5, thesaid article comprising a metal supporting element having a plurality ofcoatings thereonincluding an inner coating resulting from theapplication of substantially the y following composition: l

n Parts by weight Talc 150 Zinc oxide 150 Nitrocellulose 10Q Tricresylphosphate 35 Blown castor oil 40, Solvent 1100 and a Asuperposed outsidecoating resulting from the latter coating having a uniformly-smoothsurface characterized by being free from that pittedappearance resultingfrom the application of coatings of cellulose ester on inner coatings ofcellulose ester. f

the application of vsubstantially the following composition:

Parts byweight y Antimony oxide T 23o Plastic alkyd resin 230 Benzylcellulose of low viscosity 50 Xylene 540 Butanol 85 vEither of thesematerials or suitably varied compositions of their nature are applied tothe metal surface permitted to dry for the required length of time knownfrom the formulae used,

and then a surfacing coat of nitrocellulose such` as the one mentionedabove is applied over it to fill imperfections in the metal and act as abase V for the top coat of cellulose ether lacquers such as the'onementioned above.'

It willbe obvious to one familiar with the art that numerouscompositions of the aforementioned nature are available and suitable forthe purpose intended and that such procedure of building a iinish isreadily adaptable to vother types of rigid surfaces such as wood, pressboard, and materials of that nature.

For example, other types of cellulose ether Allwd resin solutioncomposed of 1 part of what is vknown in the trade as rezyl 1102 and 1part xylol 96 Xylol 45 Butyl alcohol (butanol) 1l Clear benzyl celluloselacquer Partsv Benzyl cellulose 100 Rezyl 1102 300 Xylene 835 Butanol 90`Butyl cellosolve 5 It.will be noted that there is a small quantity ofbutyl cellosolve (mono butyl ether of ethylene glycol) present in thisformula. This material,

while a solvent for the whole film, when used in small quantitiesdoesnot appreciably dissolve the undercoat and, materially improves thecompatibility of the resin and ether as wellas helps the flow of thefinished-coat.

White. benzyl cellulose lacquer Parts Antimony oxide 100 Rezyl 1l02 100Xylol 100 Butanol 10 Butyl cellosolve 22 39301 base 110 Xylol 119Butanol-; 13

Colored benzyl cellulose lacquer Parts Chrome green pigment j 40 Rezyl1102 150 Benzyl cellulose 'l5 Xylene 660 Butanol 63 This formulaproduces agreen lacquer -and demonstrates the use of a reduced quantityof resin in proportion to the benzyl cellulose.`

Clear lacquery Parts Benzyl cellulose 100 Alkyd` resin known in thetrade as Amberol 801 150 Dibutyl phthalate 30 Xylol '165 Butanol Butylcellosolve 8*/2 This formula demonstrates the use of the benzylcelluloselacquer in the clear state and also shows a combination of this etherwith a synthetic plasticizer and hard synthetic resin.

Clear ethyl cellulose lacquer Parts Ethyl cellulose Damar gum (dewaxed)100 Dibutyl phahalate 30 Toluene 300 Xylene 400 Butanol 'l5 This formulashows the use of ethyl cellulose with the natural resin damar anddibutyl phthalate plasticizer. The combination makes an excellent clearfinish 'for decorative purpose.

Colored ethyl cellulose lacquer Parts Para red pigment 40 Ethylcellulose 100 Alkyd resin known in'thetrade as Lewisol Dibutyl phthalate25 Xylene 770 Butanol 85 l Butylcellosolve 5 The above Aformula showsthe further use of ethyl cellulose in a red lacquer, making use of analykd type resin and synthetic plasticizer.4

These are only typical formulae and numerous other combinations ofresins in the alkyd class as well` as the phenol aldehyde class can beused.

Cellulose ether coatings of the type set forth have excellent levellingproperties and are in general very alkali and water resistant. In theapplication of cellulose ether lacquers to the process of the presentinvention, it is distinctly demonstrated that they do not soak into orsoften undercoatings prepared from cellulose esters including cellulosenitrate or cellulose acetate but on the contrary leave suchundercoatings unaffected and thereby dry to a smooth or glossy hardperfect finish.

. 'I'he proportions of ingredients in the formu- V.las given herein, arein parts by weight.

It is to be understood that the hydrocarbon solvent material for thecellulose ether lacquer,

referred to in the claims, is not considered av solvent for celluloseesters at those temperatures at which paints and lacquers are ordinarilyapplied for coating purposes.

What I claim is: 1

' 1. A process of manufacturing a coated metal object, which processcomprises applying to a surface of said object a cellulose estercomposition to form a solid film that is not dissolved by low-boilinghydrocarbons alone, applying directly to the surface of said illm asolution of cellulose ether in a solvent containing low-boilinghydrocarbon liquid in such proportion that the solvent does notsoftenthe said film, and permitting the said solution to dry on thesaidillm to thereby form a smooth, finished surface.

1 1. An article of manufacture produced by the process of claim 6, thesaid article comprising a metal supporting element having `a pluralityof coatings thereon including a priming coat, an intermediate coatingresulting from the application of substantially the followingcomposition:

n Parts by weight Tale 150 Zinc oxide 150 Nitrocellulose 100 Tricresylphosphate 35 Blown. castor oil 40 Solvent 1 100 and a superposed outsidecoating'resulting frorn l the latter coating having a uniformly smooth10 surface-clia1wacte-rized by being free from that pitted appearanceresulting from the application of coatings of cellulose ester to innercoatings of cellulose ester.

EMORY H. TRUssELL. 15

